Some sentences in the following passage contains an italicized vocabulary word or related form. After you read the passage, you will complete an exercise.

Dr. Charles Drew: Physician and Scientist

Dr. Charles Richard Drew $(1904-1950)$, an American physician and scientist, was internationally recognized as the leading authority on the preservation of human blood for transfusion. Without his work on blood plasma, numerous lives would have been lost needlessly during World War II. His pioneering efforts in blood research were also responsible for the foundation of blood banks, which continue to save lives today.

Charles Drew began his medical career at MoGill University in Montreal, Canada. He became interested in blood research as an intern. In $1938$ a Rockefeller fellowship for advanced training allowed him to pursue this interest at Columbia University's Presbyterian Hospital, where two years later he would be awarded the Doctor of Medical Science degree, actually a Ph.D. in medicine. Charles Drew was the first American black to receive this degree.

Working on techniques for synthesizing and preserving blood, Dr. Drew paid close attention to the special properties of plasma, the fluid portion of blood. Presupposing that plasma could be preserved for future emergency transfusions, he spent as much as eighteen hours a day gathering data to support this idea. In $1939$ he tested his theory empirically by setting up an experimental blood bank. His hypothesis was valid; unlike whole blood, plasma could be stored more than one week and could be administered to a person of any blood type. Drew's doctoral thesis, Banked Blood: A Study in Blood Preservation, dealt with the development of the blood bank and with the preservation and transportation of plasma. The treatise remains a definitive study of the subject.

As World War II began in Europe, Dr. Drew had further opportunity to verify his findings. He was appointed medical supervisor of the "Blood for Britain" project, which supplied Britain with badly needed blood plasma. Although some physicians at first rationalized that whole blood was preferable, Drew showed them that plasma was more efficient, especially in emergencies, when speed was crucial. After Britain no longer needed American aid, Drew was appointed director of the American Red Cross program for collecting and banking blood for the American armed services. Dr. Drew's work for both programs constituted a rebuttal to the conventional assumption that wartime casualties could be treated only in hospitals. Formerly it had been axiomatic that battlefield transfusions were impossible. Now the emergency use of plasma repudiated this idea. Trained technicians could administer the life-saving plasma, sometimes in a matter of minutes.

In peacetime Drew's work remained important as blood banks continued to save lives. Drew spent the rest of his career in various teaching and administrative posts at Howard University, where he became head of the department of surgery.

Dr. Charles Drew died of injuries resulting from a car accident. His death was ironic: in desperate need of a blood transfusion, he did not reach a hospital in time.

Each of the following statements corresponds to some sentences in the passage. Each statement contains a blank and is followed by four answer choices. Decide which choice fits best in the blank. The word or phrase that you choose must express roughly the same meaning as the italicized word in the passage. Write the letter of your choice on the answer line.

He tested his theory $\underline{?}$ by setting up an experimental blood bank. ___________

a. in practice b. step by step c. partially d. irregularly